1. Field of the Invention
The present invention relates to a liquid ejection cartridge to be used in a liquid ejection apparatus for forming an image on a recording medium such as a sheet of paper by ejecting liquid.
2. Description of the Related Art
In inkjet type recording apparatus for recording images on recording mediums (to be referred to as liquid ejection apparatus hereinafter), a liquid ejection head for ejecting liquid such as ink is driven to eject liquid droplets so as to make them hit a recording medium at respective target positions and form an image thereon.
Liquid ejection apparatus include those that are mounted by a liquid ejection cartridge that is by turn equipped with a liquid ejection head. The liquid ejection head has an electrical contact section and the liquid ejection head is electrically connected to the apparatus main body as the electrical contact section is brought into contact with the electrical connector pins of the apparatus main body. Driving signals, signals that indicate the remaining quantity of ink and other signals are exchanged between the apparatus main body and the liquid ejection head.
The electrical contact sections of liquid ejection cartridges include those that are structurally referred to as “substrate type” and those that are structurally referred to as “film type”. A “substrate type” electrical contact section has contact pads that are typically made of gold and formed on a printed substrate, which is made of glass epoxy or the like. A “film type” electrical contact section, on the other hand, has contact pads that are typically made of gold and formed on a flexible wiring film. “Substrate type” electrical contact sections are expensive if compared with “film type” electrical contact sections but are being currently broadly employed because they are highly reliable.
Japanese Patent Application Laid-Open No. 2004-358912 describes a head cartridge that is equipped with a “substrate type” electrical contact section. The head cartridge is so designed as to be fitted to the carriage of a liquid ejection apparatus main body and has an electrical contact section formed on the surface thereof to be located vis-à-vis the surface of the carriage where electrical connector pins are formed. The electrical contact section includes a plurality of contact pads by way of which drive signals, signals that indicate the remaining quantity of ink and other signals are transmitted. The contact pads are formed on a single printed substrate.
When manufacturing printed substrates, ordinarily, substrates having a predetermined size are cut to produce printed substrates exactly representing a required size. The unit cost of printed substrates is reduced as the number of printed substrates produced from a single substrate is increased, in other words, as the size of each printed substrate is reduced.
Because the electrical contact section of the head cartridge described in Japanese Patent Application Laid-Open No. 2004-358912 for electrically connecting the cartridge with the carriage is formed on a single printed substrate, the printed substrate is inevitably required to have a large size. For this reason, the unit cost of the printed substrate is high to in turn raise the cost of the head cartridge.